Castile was at war again in 1396. In the last entry of his partial chronicle of the reign of Enrique III, Pedro López de Ayala writes simply: “And in this year the King [João I] of Portugal took to Badajoz, the King Don Enrique [III of Castile] being in Sevilla.” Ayala's terse statement is perhaps unremarkable; from 1396 we can look backwards and observe near constant war for the last thirty years: the Castilian civil war from 1366–1371, a territorial dispute with Portugal in 1372–1373, a similar dispute with Navarre in 1378–79, and an attempt on the part of Juan I to claim the Portuguese throne, a debacle that lasted from 1384 to 1389. Going forward, too, Castile and its knights would constantly be at war with their neighbors in the 15th century. Throughout much of this period, the Hundred Years’ War raged between France and England, with Castilian knights often participating through piracy and naval raids on English and Portuguese territory, if not through engagements on land. For Ayala, who had lived through and participated in many of these campaigns, even being captured by the enemy twice, a new war with Portugal, which ultimately proved to be a small and insignificant campaign, would have been business as usual. Not only from the royal chronicler's perspective, but from the perspective of knights and men-at-arms, a new war would not have been a shocking development. To be sure, another theater of war opening on the western frontier meant further opportunity for the chivalric elite to exercise their sword arms and win precious honor for themselves.

What may strike the modern reader as somewhat more remarkable is that nearly all of Castile's wars in the late 14th century, and many throughout the 15th century, were fought against fellow Christians: England, Portugal, Navarre, and occasionally Aragon and other Castilians. In the same thirtyyear period that closed the 14th century, Castile fought non-Christian enemies only in small campaigns, often no more than raiding Granada, defending against raids from Granada, or fighting Muslim pirates in the Mediterranean. Given the paramount position of holy war in chivalric ideology discussed in the last chapter, why did the chivalry of late medieval Castile so consistently make war against their coreligionists?